Do you have any photo applications (In particular the one that caused me grief was FastPictureViewer). My troubleshooting steps that resolved this issue for me with 12.6.1033 version of RST were to use Microsoft sysinternals suite (procmon), Just before iastorui.exe goes belly up, it reads the registry in HKEY Class root in particular it died on .png. That led me to remember that my Microsoft calculator also had a weird display issue (transparent background and numbers were jumbled), and googling that led to fastpicture viewer.. and sure enough same symptom. Uninstall of that resolved iastorui.exe which now opens.
I have a suspsicion that app added a bunch of file associations that probably overflowed memory when it reads registry with RST.
On to my next task, which is replacing hard drive that failed... now that I can activate a new drive as a spare..
